The overall objectives of this project include examination of the pathways of transport of three different classes of antibiotics (the penicillins, cephalosporins, and aminoglycosides) into the interstitial fluid space of osteomyelitic bone and quantitation of their concentration in the interstitial fluid space of osteomyelitic bone. Bioassay has been proven to be an inaccurate technique--the beta-lactam antibiotics are inactivated by the elution process and the aminoglycosides can only be partially eluted (63%) with caustic agents such as 0.1 M sodium hydroxide. Preliminary experiments suggest that the transport mechanics for cephradine are different from those observed with beta-lactam agents. Additionally, the volume of distribution of cephradine in osteomyelitic bone is appreciably increased when compared to other beta-lactam antibiotics. Further experiments are needed to confirm and explain these observations.